 One particularly important ritual which the head of the Nakatomi clan oversaw was the "Ōharai" purification rite, performed twice every year, in which the High Priest (of the Nakatomi clan) asked the "kami" to cleanse the spirits of all of the people of their impurities.As a result of the Nakatomis' ritual position and role in the Asuka period, they were among the chief advocates of conservatism in the controversy over the introduction of Buddhism to Japan in the 6th century.However, by the time of Nakatomi no Kamatari, in the early 7th century, the clan had switched sides, possibly as a result of their loyalty and close connection to the Imperial family; following Prince Shōtoku, likely the most famous advocate of Buddhism in all of Japanese history, and later Prince Naka no Ōe, the Nakatomi helped eliminate the Soga clan, powerful and very active supporters of Buddhism, and of the current administration of the time (see Isshi Incident).